3.11-3.13 Quiz

Question 1

What type of movement occurs in microwave radiation? Why?

Answer 1

Rotational; This is due to the interaction of the dipole of the molecules interacting with the electromagnetic field of the microwave photons.

Question 2

What type of movement occurs in infrared radiation?

Answer 2

Vibrational

Question 3

What type of movement occurs in ultraviolet/visible radiation?

Answer 3

Translational

Question 4

Spectroscopy

Answer 4

Study of how matter interacts with electromagnetic radiation

Question 5

If you have a long wavelength, then you have _______ energy. If you have a short wavelength, then you have _______ energy.

Answer 5

Low; high

Question 6

If you have a long wavelength, then you have _______ frequency. If you have a short wavelength, then you have _______ frequency.

Answer 6

Low; high

Question 7

Put the three types of movement(translational, vibrational, rotational) in order from least to most energy used.

Answer 7

Rotational, vibrational, translational

Question 8

Translational movement

Answer 8

Movement from one place to another. This takes the most energy.

Question 9

Rotational movement

Answer 9

Spinning in place. This is the least amount of energy because spinning it doesn’t take much energy compared to vibrational where the bonds are elongated to vibrate.

Question 10

Vibrational movement

Answer 10

vibrating/moving in place. This takes the “middlest” amount of energy because the particles are being stretched and bended while moving in place which takes more energy than spinning.

Question 11

In infrared radiation, what type of atoms vibrate at higher frequencies?

Answer 11

Lighter atoms and stronger bonds

Question 12

What is one of the most important things that ultraviolet-visible radiation is associated with?

Answer 12

Transitions in electronic energy levels/ when electrons move from their ground state to a higher energy “excited” state.

Question 13

What does a spectrophotometer do?

Answer 13

You use it to measure the amount of light leaving a sample and comparing it to the amount of the light that entered the sample

Question 14

Two samples of copper (II) sulfate were analyzed using visible light spectroscopy. Sample One absorbed twice as much light as Sample Two.
a) What can you deduce about the concentrations of the two solutions?
b) What must be true of the solutions in order to get results from this type of spectroscopy?
c) Describe the type of changes that occur within the molecule during the process of UV-Vis spectroscopy.

Answer 14

a) The concentration of sample 1 was double the concentration of sample 2.
b) They must have a color because if they were clear they wouldn’t be able to absorb anything.
c) Energy must be absorbed (causing electrons to move to an excited state) and then emitted (the electrons fall to a lower energy state).

Question 15

How are absorbance and concentration related?

Answer 15

They are directly related; if one doubles then the other one does too

Question 16

How could one molecule absorb ultraviolet light but not visible light and another could absorb ultraviolet and visible?

Answer 16

Because one could not produce transitions between energy levels through visible light

Question 17

What is an approximate number for the wavelength of visible light?

Answer 17

Any number in the 100s

Question 18

Photoelectric effect

Answer 18

When light shines on the surface of metal and electrons can be ejected from the surface

Question 19

Photo

Answer 19

Electrons being ejected through light

Question 20

Threshold frequency
- Definition
- What happens if the frequency used is higher than the threshold frequency?

Answer 20

The amount of energy needed to remove an electron.

If a frequency is higher than the threshold frequency then the electrons will be ejected with more kinetic energy.

Question 20

Binding energy

Answer 20

How tightly the electrons are being held in the atom

Question 21

What does a high binding energy mean?

Answer 21

That the electrons are closer to the nucleus or that the nucleus has a higher charge.

Question 22

Threshold wavelength
- Definition
- What happens if the frequency used is lower than the threshold frequency?

Answer 22

The max amount of energy needed to eject an electron.

Anything shorter than the max will have enough energy to eject the electrons.

Question 23

What relationship does energy have with frequency? Wavelength?

Answer 23

Energy is directly related to frequency and wavelength is inversely related.